electromagnetic Pulser

Discussion in 'The Projects Forum' started by blipblipblur, Nov 12, 2010.

  1. blipblipblur

    Thread Starter New Member

    Nov 12, 2010
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    Heya Forum

    Im working on a project that ive had floating around in my mind for a while now but the specifics are something i hadent gone into depth about.

    what i want to build is a circuit that pulses a current to an electromagnet and uses an led pickup as a variable.

    this is to hold a magnet at a set distant from the electromagnet and when the beam is broken for the pulses to change.

    any help would be appreciated and the more the merrier as i have next to zilch knowledge of circuits

    Many Thanks

    Sam
     
  2. wayneh

    Expert

    Sep 9, 2010
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    This sounds like one of those levitating or floating magnet thingys you might have on your desk, like this:
    http://www.scientificsonline.com/levitron-world-stage-base.html

    Is that what you're wanting to do?
     
  3. blipblipblur

    Thread Starter New Member

    Nov 12, 2010
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    yer im going to use that idea and adapt and experiment with it to see just how they react

    they way im after it working is to have 3 electromagnetic "bases" with 6 circuits to allow for an alternating flux.

    the idea is that i want a magnet to levitate and the electromagnet to both push and pull one after the other, and when the led pickups get set/tripped for the pulse to change to correct it, so if the magnet gets to close the repulse works more than the attract, and vice verse

    so that one magnet can hold it in place in any position.

    im not sure if i explained it that well.
     
  4. retched

    AAC Fanatic!

    Dec 5, 2009
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    Have you drawn a sketch, or even a flow chart yet?

    That may help..because I am quite confused.
     
  5. blipblipblur

    Thread Starter New Member

    Nov 12, 2010
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    ive attached a quick drawing, led1 goes to C1 (circuit 1) each of the circuits run a current through the coils in different directions to change the polarity of the flux.

    i know im not describing it too well but its kinda complicated
     
  6. retched

    AAC Fanatic!

    Dec 5, 2009
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    Ok.. When you say LED, you actually want electronic eyes. Like a beam break switch.

    Am I right?

    And when your floating object falls and breaks a beam, another E-Magnet or set of E-magnets attract or repel to center the object again?

    Am I close? or are the red lines supposed to be wires?
     
  7. blipblipblur

    Thread Starter New Member

    Nov 12, 2010
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    thats spot on.
     
  8. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    If you use a floating "magnet", switching the polarity of the electromagnet will cause the magnet to flip over and be attracted, not repelled. If you use a steel floating object, instead of a magnet, you only need one polarity in the electromagnet, and gravity will provide the opposite attracting force.

    Ken
     
  9. blipblipblur

    Thread Starter New Member

    Nov 12, 2010
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    yer im well aware of this, but the item im going to float wont be able to flip, and the top magnet is going to only be one of 3 or more. and gravity wont be the only force acting upon it.

    so i kinda need it to alternate accordingly.
     
  10. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Just going by your sketch! If you have more parts, or a different configuration you need to spell them out. The more details you provide up front, the less fishing we have to do.

    We would rather help you solve your problem, than help solve your solution. ;)

    Ken
     
  11. blipblipblur

    Thread Starter New Member

    Nov 12, 2010
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    well tbh anything else is going to be the same as the diagram but at different angles or summing.

    the circuit i need is something to work on that diagram so that it keeps the "floter" center no matter even if its pushed up. so id like the current of flux to change direction even if that means two separate sources. id like the them to somehow work together.

    i think thats about as much information as i can provide. please ask me if theres any thing else.
     
  12. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Single coils on each of three (?) cores. Each coil is driven by a circuit called an "H-bridge". This allows the coil to be OFF or polarity A or polarity B. The H-bridge has two logic inputs. In order to control the strength of the field on each coil the power to them will need to be driven by a PWM (pulse width modulation) circuit. Plus you need to take the outputs of the photo-detectors as an analog voltage proportional to the displacement of the "floater". This looks like a job for one, or maybe three, fast microcontrollers.

    Ken
     
  13. blipblipblur

    Thread Starter New Member

    Nov 12, 2010
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    right im guessing the h-bridge is a logic chip. and the micro-controllers tell it what when to do what?

    it must be frustrating talking to someone who has no idea about electronics.

    is there different types of micro-controllers?

    btw thanks for helping out, google is hell to sive through and i couldn't find books for what i needed
     
  14. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Sorry, but you're taking on a project that's akin to someone who knows nothing about mechanics wanting to build a Formula 1 race car from scratch. This will take spoon feeding from the absolute basic in electronics, control theory, and programing to higher levels were you can actually implement this. Perhaps others would like to tackle this with you...but I'll bow out now.

    Ken
     
  15. blipblipblur

    Thread Starter New Member

    Nov 12, 2010
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    ok yer i dont blame you for bailing, but thanks for your help, i really appreciate it, its given me something to build upon.
     
  16. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    There was a PWM solution posted as a PDF here last week. It was an MIT project.

    Only difference was it levitated the magnet at one level, rather than 3, and used a hall effect sensor to test distance.
     
  17. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    The forces you are wanting to control can get out of hand remarkably fast.

    Ever bring two magnets in your hands to close together? Once they are close enough to influence each other, the human reflexes are just way too slow to even respond to the movements. Controlling them with an external flux field will be almost as hard. The best you could hope to do easily is 'push' the object repeatedly from varied directions to insure it stays in a general zone in the center. REacting to any changes in their position AFTER it had happened is asking for trouble.
     
  18. blipblipblur

    Thread Starter New Member

    Nov 12, 2010
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    yer for all i know this project might fail horribly but im not going to stop till i at least try. besides i wont need to react if it comes to fast calculated decisions then i may have to get a computer involved.

    alot of tweaking and what not will be trial and error so id be surprised if it works first time or at all.

    engineering and physics i can do its electronics that ive never learnt.
     
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